Method of making colored photographic reproductions.



UNITED I STATES PATENT. OFFICE.

J'OHNLEWISOHN, OF NEW YORK, N. Y.

METHOD OF MAKING COLORED PHOTOGRAPHIC REPRODUCTIONS.

No Drawing.

To all whom, it may concern:

Be it known that I, JOHN LEWISOHN, a citizen of the United States, and aresident of the city of New York, borough'of Man-. hattan, in the countyand State of New York, have invented a new and Improved Method of MakingColored Photographic Reproductions, of which the following is a full,clear, and exact description. I

My invention relates "generically to a method of making-reproductionsand specifically relates to the utilization of the blue coloration in ablue-print as one of the primary colors to combine with suitable red andyellow color washes or diluents to modify the blue effect to form thedesired color effects, and, at the same time, to retain the fine shadevalues and soft relatively true tones of the original blue-print.

My invention pertains to a process or method in which I make use of theoriginal blue color of a blue-print reproduction as one of the primaryspectrum colors, and

make use of red eosin for the red and aurantia for the yellow. By themixture of these three colors, I am able to obtain substantially any ofthe spectrum colors.

A. negative of a colored object is made preferably on an ordinaryorthochromatic photographic plate, having as a basis the silveremulsion, and preferably using a yellow colored screen, in order toobtain the best color values. From such a negative, an ordinaryblue-print is made, which' blue print will, of course, show up thedifferent shade values in their proper proportions. This blue-print isthen colored either wholly or in part, by applying dye or paint, but'n'eferablyred eosin and aurantia, or a mixture of the two, to modifythe blue to form any of the spectrum colors, the blue coloration showingthrough the applied washes with more or less intensity depending uponthe extent of the coating wash. Should it be desired to make all or anymaterial portion of the print either red or yellow, or any other color,in which blue is not used, the blue of the blue-print is either whollyor partially dissolved by a weak solution of nitrate of silver, whichwill fix the colors, and, at the same time, will gradually bleach outthe blue. Further, the blue-print may Specification of Letters Patent.

be washed with this solution, if it is desired to merely weaken the bluecolor of the object, after the eosin or aurantia has been applied, or amixture of the two, to form K any of the spectrum colors involved inthese two primary colors. Should it be desired to restore the bluelocally or entirely, or to darken the blue color, the blue-print isrespectively touched up or bathed with a solution of ferric chlorid, andthis ferric chlorid may be applied in stronger solution or in successionuntil that part of the object is practically black. Instead of paintingor bathing the entire print in any one of these colors, certain spacesmay be touched up locally, in order to either darken or lighten thoseparticular parts. In addition to this local treatment, the entire printmay be submerged in either of these primary colors, or any combinationof the same, to give the different color background and a difl'erenttint to the entire picture.

Having thus described my invention, I claim as new and desire to secureby Letters Patent: 1

1. The process of reproducing on blueprints from yellow screenednegatives, the color eflects resembling the natural colors and tones ofobjects while retaining the shade values inherent in such prints, whichprocess consists in locally treating the shaded portions which should bered-blue with a thin red wash, the shaded port-ions which should-beblue-yellowwith a thin yellow wash, and the shaded portions which shouldbe deficient in blue with a blue dissolving substance.

2. The process of reproducing on blueprints from yellow screenednegatives, the

color effects resembling the natural colors 3. :The process of producingon blue prints Patented Aug. 26, 1913.

Application filed January 12, 1911. Serial No. 602,196.

a plurality of color efi'eots which consists name to this specificationin the presence of in treatingf a blue print which displays a twosubscribing witnesses. plurality o shades or tones, or an portion of ablue print displaying a plui'ality of i 7 JOHN LEWISOHN' shades ortones, with a thin uniform Wash Witnesses: of a, pigment of a hue otherthan blue. W. S. ORToN,

In testimony whereof I have signed'my PHILIP D. ROLLHAUS.

